The first addition of the halogen to the pi bond produces a trans dihalide which is then converted into a tetrahalide. The trans dihalide can be prepared by simply adding one equivalent of the halogen. The reaction of alkynes with electrophiles such as Cl2, Br2, and I2 does give very ...
The synthesis of an alkyne from either a geminal dihalide or a vicinal dihalide requires a strongbaseto eliminate two moles of hydrogenhalide. Two suitable reagents for this reaction aresodiumamide inliquid ammoniaas the solvent and potassiumtert-butoxide indimethyl sulfoxide. ...
3.This type of reaction has signicant advantages, the alkyne proceeds the coupling reaction with the halogen atom as the leaving group. 卤原子作为炔烃三键活化基团和定位基,炔烃三键发生亲电加成反应; 4.This part mainly focused on the synthesis of propargylic alcohols in many methods including metal ...
The bis(η5-cyclopentadienyl)-sandwich complexes ofiron,cobalt, andnickelare readily prepared by the reaction ofsodiumcyclopentadienide with the correspondingd-metal halide. Because of their great stabilities, the 18-electron group-8 compounds ferrocene, ruthenocene, and osmocene maintain their ligand...
phosphonate group as the anchoring point for the attachment oforganic compounds onto alumina and the alkyne group,which is used to functionalise aryl halide compounds by a Sonogashira cross-coupling.The use of 1,10-phenanthroline as substrate illustrates the application of this strategy to an ...
12. Preparation and characterization of bis(tert-butyl mercaptido)tetrakis(dimethylamido)dimolybdenum(M≡M) From the reaction between Mo2Cl2(NMe2)4 and LiSR (≥2 equiv) in hexane, yellow-orange crystalline compounds of Mo2(SR)2(NMe2)4 have been isolated, where R ... MH Chisholm,JF ...
This side-reaction appears to be avoided when the synthesis is carried out with o-bromophenyl (pinacolato)boronic ester instead of ortho-dibromobenzene. Thus, reacting this halide with Ni(0) species generated in situ from the Zn reduction of NiBr2(PPh3)2 gives NiBr{o-C6H4B(pinacolato)}(...
The reaction of [Ti]Cl_2 (1) {[Ti]=(#eta#~5C_5H_4SiMe_3)_2Ti} with two equivalents of LiC ident to C-SiMe_2-C ident to CSiMe_3 (2) produces [Ti](C ident to C-SiMe_2-C ident to CSiMe_3)_2 (3). On treatment with [MX] (M = Cu: 4a X = Cl, 4b X = Br;...
2-Hydroxybenzaldehydes react with alkyl vinyl ketones in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) to yield 3-acyl-2H-chromenes (Scheme 19) <2000J(P1)1331>. The reaction proceeds via a Baylis–Hillman type pathway to form the zwitterionic intermediate 61 with subsequent cyclizati...
Under these conditions, the reaction was accompanied by precipitation of the target products, which can be easily isolated. Using this method, we obtained trans,trans-dihalo[bis(2-halocycloalkyl)]-λ4-selanes 9a,b and 10a,b in 96–99% yields (Scheme 2). The materials suitable for single...